Link between NetStandard and .Net Framework

Question

Link between NetStandard and .Net Framework

I am trying to get .Net Framework and NetStandard assemblies to communicate with each other (to find out what is possible). I currently have four projects, two Framework 4.5.2 projects and two NetStandard1.2 projects:

Framework452.Library
NetStandard12.CentralLibrary
NetStandard12.BaseLibrary
Framework452.Tests

Link Structure:

Framework452.Testslinks NetStandard12.CentralLibrary: we work by adding the NetStandard.Library nuget package to Framework452.Tests.
NetStandard12.CentralLibrarylinks NetStandard12.BaseLibrary: work without changes.
NetStandard12.CentralLibrarylinks Framework452.Library: does not work even if Framework452.LibraryNetStandard.Library nuget is installed.

Can NetStandard projects refer to Framework projects? If so, what do I need to do to make them communicate? At the moment I can add a link, but the code is not displayed.

Update

, , , Framework452.Tests:

CS0006: '~\TryNETStandard\NetStandard12.CentralLibrary\Bin\Debug\netstandard1.2\NetStandard12.CentralLibrary.dll' .

namespace Framework452.Library
{
    public class Returner452 {
        public static bool ReturnTrue() { return true; }
    }
}


using Xunit;
namespace Framework452.Tests
{
    public class Class1 {
        [Fact]
        public void FrameworkTest() {
            Assert.True(NetStandard12.CentralLibrary.Class1.Return452());
        }

        [Fact]
        public void NetStandardTest() {
            Assert.True(NetStandard12.CentralLibrary.Class1.Return12());
        }
    }
}


namespace NetStandard12.BaseLibrary
{
    public class Returner12 {
        public static bool ReturnTrue() { return true; }
    }
}


using Framework452.Library;
using NetStandard12.BaseLibrary;
namespace NetStandard12.CentralLibrary
{
    public class Class1
    {
        public static bool Return452() { return Returner452.ReturnTrue(); }
        public static bool Return12() { return Returner12.ReturnTrue(); }
    }
}